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/* $OpenBSD: privsep_fdpass.c,v 1.8 2012/04/04 17:24:50 deraadt Exp $ */ |
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/* |
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* Copyright (c) 2002 Matthieu Herrb |
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* Copyright (c) 2001 Niels Provos <provos@citi.umich.edu> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER |
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* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING |
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* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <sys/uio.h> |
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#include <err.h> |
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#include <errno.h> |
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#include <fcntl.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include "privsep.h" |
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void |
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send_fd(int sock, int fd) |
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{ |
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struct msghdr msg; |
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union { |
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struct cmsghdr hdr; |
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char buf[CMSG_SPACE(sizeof(int))]; |
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} cmsgbuf; |
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struct cmsghdr *cmsg; |
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struct iovec vec; |
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int result = 0; |
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ssize_t n; |
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memset(&msg, 0, sizeof(msg)); |
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if (fd >= 0) { |
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msg.msg_control = (caddr_t)&cmsgbuf.buf; |
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msg.msg_controllen = sizeof(cmsgbuf.buf); |
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cmsg = CMSG_FIRSTHDR(&msg); |
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cmsg->cmsg_len = CMSG_LEN(sizeof(int)); |
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cmsg->cmsg_level = SOL_SOCKET; |
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cmsg->cmsg_type = SCM_RIGHTS; |
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*(int *)CMSG_DATA(cmsg) = fd; |
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} else |
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result = errno; |
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vec.iov_base = &result; |
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vec.iov_len = sizeof(int); |
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msg.msg_iov = &vec; |
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msg.msg_iovlen = 1; |
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if ((n = sendmsg(sock, &msg, 0)) == -1) |
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warn("%s: sendmsg(%d)", __func__, sock); |
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if (n != sizeof(int)) |
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warnx("%s: sendmsg: expected sent 1 got %ld", |
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__func__, (long)n); |
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} |
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int |
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receive_fd(int sock) |
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{ |
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struct msghdr msg; |
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union { |
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struct cmsghdr hdr; |
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char buf[CMSG_SPACE(sizeof(int))]; |
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} cmsgbuf; |
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struct cmsghdr *cmsg; |
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struct iovec vec; |
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ssize_t n; |
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int result; |
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int fd; |
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memset(&msg, 0, sizeof(msg)); |
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vec.iov_base = &result; |
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vec.iov_len = sizeof(int); |
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msg.msg_iov = &vec; |
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msg.msg_iovlen = 1; |
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msg.msg_control = &cmsgbuf.buf; |
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msg.msg_controllen = sizeof(cmsgbuf.buf); |
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if ((n = recvmsg(sock, &msg, 0)) == -1) { |
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warn("%s: recvmsg", __func__); |
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return -1; |
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} |
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if (n != sizeof(int)) |
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warnx("%s: recvmsg: expected received 1 got %ld", |
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__func__, (long)n); |
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if (result == 0) { |
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cmsg = CMSG_FIRSTHDR(&msg); |
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if (cmsg == NULL) { |
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warnx("%s: no message header", __func__); |
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return (-1); |
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} |
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if (cmsg->cmsg_type != SCM_RIGHTS) |
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warnx("%s: expected type %d got %d", __func__, |
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SCM_RIGHTS, cmsg->cmsg_type); |
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fd = (*(int *)CMSG_DATA(cmsg)); |
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return (fd); |
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} else { |
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errno = result; |
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return (-1); |
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} |
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} |